<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="app">
        <img :src="imgsrc[index]" alt="">
        <button @click='btn' v-show="index!=0">dian</button>
        <button @click='btq' v-show="index<imgsrc.length-1">dinq</button>
    </div>
    <script src="../node_modules/vue/dist/vue.js"></script>
    <script>
        var app = new Vue({
            el: '#app',
            data: {
                imgsrc: ['./img/45.png', './img/48.png', './img/45.png', './img/48.png'],
                index: 0
            },
            methods: {
                btn: function() {
                    this.index--

                },
                btq: function() {
                    this.index++
                }
            }
        })
    </script>
</body>

</html>